Engines may utilize recirculation of exhaust gas from an engine exhaust system to an engine intake system, a process referred to as exhaust gas recirculation (EGR), to reduce regulated emissions. In some examples, a group of one or more cylinders may have an exhaust manifold that is selectively coupled to an intake passage of the engine such that the group of cylinders is dedicated, at least under some conditions, to generating exhaust for EGR. Such cylinders may be referred to as “donor cylinders.” Further, some EGR systems may include multiple valves to direct exhaust from the donor cylinders to an intake passage and/or an exhaust passage based on a desired amount of EGR.
In one example, exhaust from the donor cylinders may be directed to the exhaust passage upstream of a high pressure turbine of a high pressure turbocharger (e.g., the high pressure turbine may be in series upstream from a turbine of a second turbocharger that operates at a relatively lower pressure). Under some conditions, it may be desirable for the exhaust to bypass the high pressure turbine, and as such, the exhaust system further includes a high pressure turbine bypass with a wastegate. In such an example, however, a relatively large amount of space is needed to accommodate the various exhaust gas passages, bypasses, valves, etc. and packaging space may be limited.